1. Technical Field
Embodiments of the invention relate generally to navigation systems. Certain embodiments more particularly relate to techniques for representing a traversed course in a displayed map.
2. Background Art
Existing mobile devices provide navigation functionality to variously identify a current device position, to receive input from a user which specifies a desired destination, and to display to the user a map showing a proposed route from the current position to the desired destination. A mobile device's navigation system typically receives Global Positioning System (GPS) information as a user navigates toward such a desired destination. Based on such GPS information, the navigation system updates map information describing the current device position and/or the recommended route to the desired destination. Typically, the recommended route is comprised of one or more predetermined component routes along various roads, highways, bikepaths, walkways and/or the like.
However, such functionality of existing navigation systems is of little or no use in certain everyday situations for users of mobile devices. For example, people visiting large or complex buildings (e.g. shopping malls, convention centers, hospitals, etc.) quite often find it difficult to remember a course by which they came into the building and/or a course taken within the building during some period of time. Moreover, such courses are often arbitrary—e.g. where the user does not plan the course prior to or even during traversal—and do not follow any particular predetermined route (or predetermined component route) along a road, walkway, etc. Furthermore, people navigating in such a building often find that, in hindsight, they would like to return to some mid-course position or region which they cannot remember or clearly specify. For example, people navigating in a mall or other such building often misplace personal belongings (such as umbrellas, purses, etc.) and need to retrace their course since they do not remember when or where they lost their belongings. Further still, while a user of a mobile device navigates in such a building, the mobile device often has inconsistent or non-existent access to GPS signals.
Current navigation and mapping techniques fail to address various problems posed by situations such as those described above.